1. CH 4
Carbon Compounds

2. Carbon is the backbone of life
Living organisms consist mostly of carbon-based compounds.
Carbon is unparalleled in its ability to form large, complex, and diverse molecules.
Proteins, DNA, carbohydrates, and other molecules that distinguish living matter are all composed of carbon compounds.

3. Organic Molecules and Origin of Life
Stanley Miller’s classic experiment demonstrated the abiotic synthesis of organic compounds.
Experiments support the idea that abiotic synthesis of organic compounds, perhaps near volcanoes, could have been a stage in the origin of life.

4. EXPERIMENT
“Atmosphere”
Electrode
Condenser
CH4 H2
NH3
Water vapor
Cooled “rain” containing organic molecules
Cold water
Sample for chemical analysis
H2O “sea”

5. Carbon can bind to other molecules
Electron configuration is the key to an atom’s characteristics.
Electron configuration determines the kinds and number of bonds an atom will form with other atoms.

6. With four valence electrons, carbon can form four covalent bonds with a variety of atoms.
This ability makes large, complex molecules possible.
In molecules with multiple carbons, each carbon bonded to four other atoms has a tetrahedral shape.
However, when two carbon atoms are joined by a double bond, the atoms joined to the carbons are in the same plane as the carbons.

7. Name and Comment
Molecular
Formula
(a) Methane
(b) Ethane
CH4
Ball-and-
Stick Model
Space-Filling
Model
(c) Ethene (ethylene)
C2H6
C2H4
Structural

8. The electron configuration of carbon gives it covalent compatibility with many different elements.
The valences of carbon and its most frequent partners (hydrogen, oxygen, and nitrogen) are the “building code” that governs the architecture of living molecules.

9. Hydrogen
(valence  1)
Oxygen
(valence  2)
Nitrogen
(valence  3)
Carbon
(valence  4)

10. Carbon atoms can partner with atoms other than hydrogen; for example:
Carbon dioxide: CO2
Urea: CO(NH2)2
O = C = O
Urea

11. Molecular diversity arising from Carbon Skeleton diversity
Carbon chains form the skeletons of most organic molecules.
Carbon chains vary in length and shape.

12. (a) Length
Ethane
1-Butene
(c) Double bond position
2-Butene
Propane
(b) Branching
(d) Presence of rings
Butane
2-Methylpropane
(isobutane)
Cyclohexane
Benzene

13. Hydrocarbons
Hydrocarbons are organic molecules consisting of only carbon and hydrogen.
Many organic molecules, such as fats, have hydrocarbon components.
Hydrocarbons can undergo reactions that release a large amount of energy.

14. Nucleus
Fat droplets
(b) A fat molecule
(a) Part of a human adipose cell
10 m

15. Isomers
Isomers are compounds with the same molecular formula but different structures and properties:
Structural isomers have different covalent arrangements of their atoms.
Cis-trans isomers have the same covalent bonds but differ in spatial arrangements.
Enantiomers are isomers that are mirror images of each other.

17. (a) Structural isomers
(b) Cis-trans isomers
(c) Enantiomers
cis isomer: The two Xs are on the same side.
trans isomer: The two Xs are on opposite sides.
CO2H
CH3 H
NH2
L isomer
D isomer

18. Enantiomers are important in the pharmaceutical industry.
Two enantiomers of a drug may have different effects.
Usually only one isomer is biologically active.
Differing effects of enantiomers demonstrate that organisms are sensitive to even subtle variations in molecules.

19. L-Dopa

20. Drug
Ibuprofen
Albuterol
Condition
Effective
Enantiomer
Ineffective
Pain; inflammation
Asthma
S-Ibuprofen
R-Ibuprofen
R-Albuterol
S-Albuterol

21. Few groups are key to Biological Function
Distinctive properties of organic molecules depend on the carbon skeleton and on the molecular components attached to it.
A number of characteristic groups can replace the hydrogens attached to skeletons of organic molecules.

22. Groups most important to function of life
Functional groups are the components of organic molecules that are most commonly involved in chemical reactions.
The number and arrangement of functional groups give each molecule its unique properties.

23. Estradiol
Testosterone

24. The seven functional groups that are most important in the chemistry of life:
Hydroxyl group
Carbonyl group
Carboxyl group
Amino group
Sulfhydryl group
Phosphate group
Methyl group

27. Energy source for cellular processes
One phosphate molecule, adenosine triphosphate (ATP), is the primary energy-transferring molecule in the cell.
ATP consists of an organic molecule called adenosine attached to a string of three phosphate groups.
Adenosine

28. Adenosine
Reacts
with H2O
Inorganic
phosphate
ATP
ADP
Energy